COPPER METABOLISM

1. Copper Metabolism
Gandham. Rajeev

2. • Introduction
• Sources & RDA
• Metabolism
• Biochemical functions
• Abnormal copper metabolism
• RGUHS Questions
Copper Metabolism

3. • Total body copper is about 100 mg.
• Present in all tissues.
• Sources:
• Shellfish, liver, kidney, egg yolk, cereals &
green leafy vegetables.
• Milk is a poor source.
• RDA:
• 2 to 3 mg/day.

4. • Metabolism:
• Absorbed from upper small intestine.
• Absorbed copper is transported to the liver
bound to albumin & exported to peripheral
tissues mainly as ceruloplasmin & albumin.
• Metallothionein is a transport protein that
facilitates copper absorption.
• Copper is excreted through bile.

5. • Phytate, zinc & molybdenum decrease copper
uptake.
• Plasma copper: 100 – 200 mg/dl.
• Decreased copper levels – observed in nephrotic
syndrome, malabsorption, malnutrition.
• Increased copper levels – observed in infection &
malignancy.
• Plasma ceruloplasmin: 25 – 50 mg/dl.
• It is also called ferroxidase.

6. Biochemical functions
• Copper is an essential constituent of several
enzymes.
1. These include cytochrome oxidase, catalase,
tyrosinase, superoxide dismutase,
monoamine oxidase, ascorbic acid oxidase,
ALA synthase, phenol oxidase and uricase.
2. Copper is involved in many metabolic
reactions.

7. 3. Copper is necessary for the synthesis of
hemoglobin (Cu is a constituent of ALA
synthase).
4. Lysyl oxidase (a copper-containing enzyme)
is required for the conversion of certain lysine
residues of collagen & elastin to allysine
which are necessary for cross-linking.

8. 5. Ceruloplasmin serves as ferroxidase & is
involved in conversion of iron from Fe2+ to
Fe3+
6. Copper is necessary for the synthesis of
melanin & phospholipids
7. Development of bone & nervous system
(myelin) requires Cu.

9. 1. Menke’s kinky hair syndrome
• It is a rare disorder & sex linked
• Caused by mutation in the gene that codes for
copper binding P type ATPase in the intestinal
mucosal cell, defect in the transport of copper
from intestinal mucosal cell to blood.
• This results in deficiency of copper.
Abnormal metabolism of copper

10. • Features:
• Males are affected.
• Decreased copper in plasma & urine, anemia,
depigmentation of hair (kinky hair or silky
hair), growth failure, mental retardation,
vascular defects (lesions of the blood vessels).
• Treatment: No effective treatment.

12. Wilson’s disease
• Wilson’s disease (hepatolenticular
degeneration) is a rare genetic disorder.
• Autosomal recessively inherited disorder.
• It is caused by mutation in the gene that
codes for copper binding P type ATPase in
liver leading to defect in the transport of
copper & secretion of ceruloplasmin from the
liver.

13. • This results in accumulation of copper in the
liver & other tissues of the body.
• Disease is a fatal and death occurs at early
life.

15. Characteristics
• Copper is deposited in abnormal amounts in
liver & lenticular nucleus of brain.
• This may lead to hepatic cirrhosis & brain
necrosis.
• Low levels of copper and ceruloplasmin in
plasma with increased excretion of copper in
urine.

16. • Copper deposition in kidney causes renal
damage.
• This leads to increased excretion of amino
acids, glucose, peptides & hemoglobin in urine.
• Intestinal absorption of copper is very high,
about 4-6 times higher than normal.

17. Probable causes of Wilson's disease
• A failure to synthesize ceruloplasmin or an
impairment in the binding capacity of copper
to this protein or both.
• Copper is free in the plasma, it easily enters
the tissues (liver, brain, kidney), binds with the
proteins & gets deposited.
• Albumin bound copper is either normal or
increased

18. • Symptoms:
• Liver damage leading to cirrhosis, renal
tubular damage and Kayser-Fleisher rings
(brown pigment around the iris) at the edges
of the cornea.
• Treatment:
• Includes diet low in copper and
administration of copper chelator, D-
penicillamine.

19. Kayser-Fleisher rings

20. RGUHS Questions
1. Write in detail about copper metabolism.
2. Wilson’s disease
3. Ceruloplasmin
4. Disorders of copper metabolism